Posted by Samantha on Monday, April 16, 2012 at 12:46pm.
I need help trying to write out these binomial expansions: they all need to be raised to the 8th power. Thanks
1. (x + y) 2. (w + z) 3. (x - y) 4. (2a + 3b)
- Now explain how your answer for #1 could be used as a formula to help you answer each of the other items. In each case, for #2, 3 and 4, tell what would x equal and what would y equal.
- Without writing out the whole polynomial, find the 16th term is (x + y)19. Explain how you constructed it.
- Math - Steve, Monday, April 16, 2012 at 1:36pm
Recall your Pascal's triangle for the expansion of (a+b)^n
On the nth row, you have the kth element: C(n,k)a^(n-k+1)b^(k-1)
That is, on the 8th row you have
C(8,0)a^8b^0 C(8,1)a^7b^1 . . .
= a^8 + 8a^7b + 28a^6b^2 + ... + 28a^2b^6 + 8ab^7 + b^8
There are lots of places online where you can find Pascal's triangle.
So, for this problem, the 16th term of the 19th row is
C(19,15)(2a)^4(3b)^15 = 3876(2a)^4(3b)^15
- Math - PS - Steve, Monday, April 16, 2012 at 1:37pm
Oops. It was just (x+y)^19. My bad.
C(19,15)x^4(y^15 = 3876x^4y^15
Answer This Question
More Related Questions
- math - The question that have is to simplify and write the answer in ...
- LA a book summary help - i need to do a book summary about the last apprentice...
- Pre-Algebra - Find each product or Quotient. Express using exponents. 1. The ...
- 8th Grade Algebra - (b^2-10b+21)/(b^2-11b+28) I need help trying to figure out ...
- Statiatics - Need help please. Determine whether each experiment is a binomial ...
- 8th grade Math - I'm actually in 7th grade, but I'm doing 8th grade pre-algebra...
- Fibonacci numbers - I have been working on this question all day and can not ...
- Math (Trying to understand) 4th - Hi I need help with something. I need to ...
- 8th grade - okay, heres the deal tomorrows my english exam in which i need to ...
- Algebra 2 ... - * Simplify. a to the power of 4/3 times c ^1/6 all over 9b^3...